Flashback structure for a catheter assembly



FIG. 1 is a left side elevational view of a flashback structure for a catheter assembly, showing my new design, the right side being a mirror image;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a front end view thereof;

FIG. 5 is a rear end view thereof. 

The ornamental design for a flashback structure for a catheter assembly, as shown and described. 